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Methane (CH4)

  • Methane is a gas and is
  • made of one molecule of carbon and four molecules of hydrogen
  • odorless and colorless
  • lighter than air

Methane is usually given off by cows, sheep, and other livestock. These animals have anaerobic bacteria inside their digestive system and large amounts of methane is given off during their digestive process. One example of methane that is formed by cows is through the manure that they 'produce'.

Methane is also a greenhouse gas.

Methane is explosive, and can from such a mixture with air levels as low as 5%.

Josea Evan 2o212


Nitrogen Dioxide (NO2)

Done by Joel Chan (5), 2O1

TOXIC.png(Extremely Toxic)

Other names: Nitrogen (IV) Oxide

Nitrogen dioxide is one of many nitrogen oxides. It is a highly corrosive and reactive toxic gas. It is reddish-brown in colour, and has a sharp, biting odour.
In comparison with its components...

Colour: Colourless
Odour: Odourless
Taste: Tasteless
State (at room temperature): Gas

Colour: Very, very pale blue
Odour: Odourless
Taste: Tasteless
State: Gas

Nitrogen dioxide is toxic by inhalation! Fuming nitric acid is a potential source of exposure to the gas. A low dose of the gas is already potentially fatal. Symptoms of impaired gas exchange, and anaesthesia of the nose are signs of inhalation.

Nitrogen dioxide is also produced by testing of nuclear weapons! Large explosions (such as volcanic eruptions) can produce red-coloured mushroom-shaped pyrocumulus clouds. The red colour is caused by nitrogen dioxide.

Nitrogen dioxide is a major pollutant, and contributes greatly to acid rain.

There is a link between nitrogen dioxide and Sudden Infant Death Syndrome.

On the bright side, however, nitrogen dioxide does contribute in helping to patch up our ozone layer!


by Ronald Chiang, 2O106

Carbon +Hydrogen = Benzene

What is Benzene?
Benzene is an organic chemical compound.
Benzene evaporates into the air very quickly. Its vapor is heavier than air and may sink into low-lying areas. Benzene dissolves only slightly in water and will float on top of water.
It is composed of 6 carbon atoms in a ring, with 1 hydrogen atom attached to each carbon atom, with the molecular formula C6H6.
Why is Benzene harmful?
Benzene works by causing cells not to work correctly. For example, it can cause bone marrow not to produce enough red blood cells, which can lead to anemia. Also, it can damage the immune system by changing blood levels of antibodies and causing the loss of white blood cells.


Carbon Monoxide

Marcus Seah 2O1(21)

Carbon Monoxide also known as carbonous oxide is a colorless, odourless, and tasteless gas that is slightly lighter than air and is formed from the bonding of two harmless elements, carbon and oxygen. Carbon has allotropes namely, diamond, graphite etc which are useful. Oxygen is essential to the survival of mankind.

It is produced by the incomplete burning of various fuels, including coal, wood, charcoal, oil, kerosene, propane, and natural gas.Products and equipment powered by internal combustion engines such as cars, lawn mowers, and power washers also produce Carbon Monoxide.
Carbon Monoxide is also produced in small quantities during normal animal metabolism and is thought to have a biological function. However, inhaling in high concentrations would prove toxic to humans and animals alike. Carbon Monoxide is short-lived and exists in varying quantities in the Earth's atmosphere as it is reactive to oxygen in the formation of carbon dioxide and ozone.

Chemical Equation= C+O
Chemical Equation= C+O

Carbon Monoxide is a covalent bond in which 2 carbon electrons and 4 oxygen electrons are shared

Rapidly developing, high level CO exposures (e.g., associated with use of generators in residential spaces) would lead to victims rapidly becoming mentally confused, and losing muscle control without having first experienced milder symptoms namely, headache, fatigue, shortness of breath and would likely die if not rescued.

Nitric Oxide

Joshua Tham, 2O1 (13)

Chemical Equation

Nitrogen + Oxygen = Nitric Oxide

Chemical Properties (at room temperature)
  • Colourless
  • Odourless
  • Tasteless
  • Non-metal gas.
  • Colourless
  • Odourless
Nitric Oxide
  • Colourless gas
  • Sweet odour
  • Slightly soluble in water
  • Highly reactive

Nitric Oxide is extremely toxic by inhalation, and symptoms of over-exposure may not become apparent for up to 72 hours. Although the gas itself is non-flammable, it accelerates combustion and increases the risk of fire and explosion in combustible and flammable materials.



Methane is usually given off by cows and it is a chemical compound, CH4, and is formed by one carbon atom and 4 hydrogen atoms.
When burned in air, the carbon atom combines with 2 oxygen atoms to form one carbon dioxide molecule, CO2, and the four hydrogen atoms combine in pairs with one oxygen atom to form two H20 molecules.
CH4 + O2 + 2O = CO2 + 2H20.
This is an exothermic reaction, meaning that it releases heat, methane is also a greenhouse gas.

Methane is a flammable gas that is hard to spot as it is colourless and odourless. It is used primarily as fuel to make heat and light. It is also used to manufacture organic chemicals and can be found released by cows or decaying of natural materials.

Methane can form an EXPLOSIVE mixture in air at levels as low as 5 percent. You can smell leaking methane only when commercial gas utility companies add a chemical smell to it or when it mixes naturally with hydrogen sulfide, causing a "rotten egg" smell. If you can smell it, the level may be too high to be safe.

Thus, methane is harmful to us.



Done by Ryan Koh(14) 2O1

The harmful compound is methane(CH4). Methane is a greenhouse gas, and is rather dangerous and poisonous. It is colourless, odorless and it is also released during decomposition or passing of gas in humans.:P Methane is a compound made up of carbon and four hydrogen atoms, and is rather flammable and explosive. It also might cause suffocation during inhalation of the gas. The constituent elements, namely carbon and hydrogen, are rather common and harmless in our lives. The bonding is illustrated below:


Sulfur Dioxide

by Toh Wei Xiong(31) 2O1

My harmful compound is sulfur dioxide, SO2. It is a toxic gas released by volcanoes as well as some industrial process. Coal and petroleum often contain sulfur compounds and during burning of these fuels, sulfur dioxide is generated unless the sulfur compounds were removed before the burning process. Sulfur dioxide is harmful in large amounts and is known to cause increased respiratory symptoms and diseases, difficulty in breathing and early death. In the presence of some compounds, sulfur dioxide can react to form acid rain, damaging the environment. Both the elements sulfur and oxygen are harmless to us and we are exposed to oxygen in large amounts. However, after reacting to form sulfur dioxide, they become a toxic compound.


Nitric oxide

nitrogen + oxygen = nitric oxide

My harmful compound is nitric oxide, and its fomula is NO. It is formed by nitrogen and oxygen. At room temperature, Nitric Oxide is colourless, nonflammable and toxic gas with an irritating odour. It is extremely toxic if inhaled. Both nitrogen and oxygen are harmless to us, and it is also present in the air around us. However, when combined together, they form a toxic substance nitric oxide. Nitric oxide is also used for bodybuilding, as it causes vasodilation (an expansion of the internal diameter of blood vessels), which in turn leads to an increased blood flow, oxygen transport and a reduction in blood pressure. NO2, which is used in bodybuilding, lets your muscles experience an extended pump.

- Tan Wen Liang (28)


My harmful compound is ammonia, and its formula is NH3. From its formula, it is formed by nitrogen and hydrogen. Thankfully, nitrogen (78 percent of our atmosphere) is not harmful. It is colourless, odourless and tasteless. It was isolated in 1772 by Scottish chemist and its name originated from the French word nitrogène, which derived from Greek meaning « saltpeter » and « to generate ». Hydrogen is also not toxic, and it is highly flammable. It is the mostabundant gas is the atmosphere, consituting roughly 75 percent of the Universe’s chemical elemental mass. These 2 elements are chemically bonded by covalent bonding and ammonia is processed commercially using the Haber-Bosch process.

Ammonia is highly toxic and graded 3 on health by NFPA, as toxic as chlorine. Breathing the fumes for too long is fatal.

Futhermore, it can be combined with harmless methane gas to form hydrogen cynaide, used by Nazis in gas chambers, and rated 4 on health by NFPA.

~Władek F. S.

external image mmm.jpg

Loh Jian Cong

Carbon (C) + Oxygen (O) → Carbon Monoxide (CO)
Carbon monoxide is a colourless, odourless and tasteless gas. Carbon monoxide, a harmful compound that can be toxic to humans and animals when encountered in higher concentrations, is formed when carbon and oxygen, both harmless elements, react together. Carbon monoxide poisoning is the most common type of fatal air poisoning in many countries. Carbon monoxide is colourless, odourless, and tasteless, but highly toxic. It combines with haemoglobin to produce carboxyhaemoglobin, which is ineffective for delivering oxygen to bodily tissues. Carbon monoxide consists of one carbon atom and one oxygen atom, connected by covalent bonding.


Emil Tay
My harmful compound is carbon monoxide, and its formula is CO. From its formula, it is formed by 1 atom of carbon and 1 atom of oxygen. The two elements are chemically bonded by covalent bonding. Carbon monoxide is toxic and has a flammability rating of 4, reactivity rating of 2, and health rating of 4.(Source from NPFA)
dot_and_cross.gifDot and cross diagram of Carbon Monoxide
Key: X: Electron of carbon Y: Electron of oxygen


My report on elements. Sean Ng 20124

The two harmless elements are carbon and oxygen. The deadly compound they form is carbon monoxide.
Carbon: Carbon comes in a few forms, diamond, graphite, etc. Most, if not all of its forms are harmless. Diamonds are used in the making of jewellery and for decorational purposes. Graphite is used to make pencil leads and refined graphite are used to make the carbon frames of sports cars. Graphite is commonly called lead; however, do not confuse it with the metallic, poisonous element with the same name.
Carbon is known to form almost ten million chemical compounds, all thanks to its affinity for bonding with other small atoms. Carbon also has the highest sublimation point of all elements so far, as it sublimes around 3,900K (around 3627 Celsius). Diamond and Graphite are poles apart; one is the hardest material in the universe and one is the softest. Carbon is versatile and this results in it being one of the most useful elements to man.
external image 250px-Diamond-and-graphite-with-scale.jpg
Oxygen: Oxygen usually appears as a colorless gas, and in its liquid state a pale-blue liquid. Two oxygen atoms bond together to form dioxygen, a pale blue, odorless, tasteless diatomic gas. Its formula is O2. By mass, oxygen is the third most abundant element by mass in the earth’s crust, and has the second highest electronegativity of all the elements. (Yes, electronegativity.) Oxygen also comprises most of the masses of living organisms. Oxygen is used in the making of steel,textiles and plastics.Other uses include life support and being used as a rocket propellant. Oxygen comes from Greek and means "acid forming." When oxygen was named, scientists thought all acids contain oxygen, but now we know that's not true, although most of them do (acetic acid, CH3COOH, which is the acid in vinegar, and sulfuric acid, H2SO4 or oil of vitriol, do contain oxygen, but hydrochloric acid, HCl, does not.)
Although pure oxygen can cause seizures when inhaled directly, small amounts of oxygen do not cause harm.

external image images?q=tbn:ANd9GcQ8UpTWAAv5PsI9_uFYb5mvRbWzGpiox9sSpQ13sVjOO0B9u49AbAßLiquid oxygen
The Harmful product: Carbon monoxide
Carbon monoxide consists of one carbon atom and one oxygen atom, connected by a triple bond that consists of two covalent bonds as well as one dative covalent bond.
Carbon monoxide is produced from the partial oxidation of carbon-containing compounds; it forms when there is not enough oxygen to produce carbon dioxide (CO2), such as when operating a stoveor an internal combustion engine in an enclosed space. In the presence of oxygen, carbon monoxide burns with a blue flame, producing carbon dioxide. Coal gas which was widely used before the 1960s for domestic lighting, cooking, and heating, had carbon monoxide as a significant constituent...
Carbon monoxide is a toxic gas, however being that it is colorless, tasteless, odorless and initially non-irritating, it is very difficult to be detected. Produced by motor vehicles and coal stoves, the symptoms of mild acute poisoning include lightheadedness, confusion, vertigo, headaches and flu-like effects. Long term sequelae would occur following acute poisoning.
The adverse effects caused by inhaling carbon dioxide due to it combining with hemoglobin, reducing the amount of oxygen that can be carried by the blood. Carboxyhemoglobin can revert to hemoglobin, but the recovery takes time because the HbCO complex is fairly stable. Treatment of poisoning largely consists of administering 100% oxygen or providing hyperbaric oxygen therapy, although the optimum treatment remains controversial. Oxygen works as an antidote as it increases the removal of carbon monoxide from hemoglobin, in turn providing the body with normal levels of oxygen. Intentionally inhaling carbon monoxide is a infamous way to commit suicide.
Preventive measures:
  • Install carbon monoxide detectors
  • Switch the car engine off when you are not using it
  • Avoid industrial areas
Two harmless substances. Who knew that they could be so harmful when combined?

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NYU (n.d.). Carbon. MathMol. Retrieved from
Chemicool (n.d.). Carbon Element Facts. Chemicool. Retrieved from, S. (n.d.). The Element Carbon. Jefferson Lab. Retrieved from
Periodic Table (n.d.). What is Carbon? Element Properties & Periodic Table Info. Periodic Table.
Retrieved from (n.d.). Oxygen Facts. Chemistery. Retrieved from
Radiochemistry Society ELEMENT: OXYGEN.
Retrieved from
Wikibooks The Elemets/Oxygen. Retrieved from States Environmental Agency Carbon Monoxide (CO). Retrieved from


Written by Sean Ng 2O124

Ng Joong Hwee

Carbon Monoxide is made up of a carbon atom and a oxygen atom. Carbon is present in many forms for example diamond and graphite(lead). As a diamond, it is transparent yet as graphite, it is opaque and black. Oxygen is useful as it can help scuba divers stay longer underwater with the compressed oxygen from the oxygen tank and can be used for medical purposes to sustain life

The two atoms are bonded using covalent bonding, by contributing two atoms each, to obtain an octet structure. Carbon(C) has 4 valence electrons and Oxygen(O) has 6 valence electrons. Carbon Monoxide is colourless yet it damage cannot be overlooked. It combines with hemoglobinto to produce carboxyhemoglobin in the bloodstream, which blocks blood cells from delivering oxygen to body tissues. When oxygen is cut for as long as 3 minutes, the person dies.

Dot and cross diagram

Key: x-electron of oxygen

dot-electron of Carbon

Key: dot- electron of Carbon Cross-electron of oxygen

Hydrogen Sulfide (H2S)

Hydrogen Sulfate is a harmful gas that may cause instant coma or death when in high concentrations and it is naturally produced by waste matter of animals. It is formed by bonding 2 Hydrogen (H) atoms and a Sulfur (S) atom.

The valence electron of Hydrogen (H) is 1 and the valence electron of Sulfur (S) is 6. Thus, 2 more valence electrons is needed for sulfur to be stable. The 2 valence electrons are provided by 2 Hydrogen atoms. Through this bonding, the 2 Hydrogen atoms also have a full valence shell and therefore it is stable.


Methane (CH4)

Formed from: Hydrogen and Carbon

Methane is an odorless, colorless flammable gas. Its main purpose is to be used as fuel to make heat and light energy. It is produced in large quantities by mainly livestock such as cows and pigs.

(Image taken from

(Edited by David T. Sentosa)

Why is Methane harmful?

Breathing too much methane is harmful because the methane takes away the oxygen in your lungs, making you feel breathless. If the person being exposed to high amounts of methane is not given fresh air quickly, he might suffer from asphyxia* which might kill him.

*Asphyxia: Severe lack of oxygen in the body

Methane is formed through covalent bonding. Carbon and Hydrogen contributes an electron each. Electrons in the valence shell of carbon is shared with one hydrogen atom.





Done by David 'America' Sentosa

© Copyright 2012 David T. Sentosa. All Rights Reserved



  • Formaldehyde is a highly toxic substance (to all animals) regardless of how it is ingested.
  • Ingesting as little as 11.1ml of Formaldehyde will kill an adult (ouch).
  • Formaldehyde is also corrosive upon contact with water, and can cause heavy damage to our mouth, gullet and stomachs.
  • At concentrations as little as 0.1ppm of Formaldehyde in the air can irritate eyes and nose, while at high concentrations, this can cause headaches, burning sensations in the throat and difficulty breathing.

Formaldehyde is made up of Oxygen, Carbon and Hydrogen (sound familiar? lolollollolollollolol ), which are harmless.

Done by Shaun Pek
2O1, 26

Hydrogen Cyanide

Formed through the combination of carbon, nitrogen and hydrogen the resulting chemical formula would be HCN.

Carbon (C) + Nitrogen (N)+ Hydrogen (H)Hydrogen Cyanide (HCN)

external image cyanide.jpg Cyanide pill

In WWII, most nazi german spies would carry a cyanide pill in their mouth in case they were caught. If they were caught or found out, the would swallow the pill and they would die in a matter of seconds. These german soldiers would rather die for their country than be tortured about information on their country.

Anyway, cyanide is made up of 3 harmless elements. Carbon can be used for the making of crude oil and coal. Nitrogen is used to store frozen food packages while hydrogen is used to cool water in generators. All these useful and harmless elements combined together can make the deadly poison cyanide. This is the dot and cross diagram for cyanide.
Science_Harmful_Compund_-_Hydrogen_Cyanide_-_Dot_&_Cross_Diagram.png<----- Done by myself

Isaac Ray Pereira (9) 2O1

Lucas Teo
My harmful compound is nitric oxide and its formula is NO. It is formed using 1 atom of oxygen and 1 atom of nitrogen.
Nitrogen is a chemical element that has the symbol N and the atomic number of 7. Nitrogen is not reactive at standard temperature and pressure and is the largest constituent in the Earth's atmosphere. Oxygen is also a chemical element that has the symbol O and the atomic number 8. Oxygen is required by all living things and consists of 21 percent of the Earth's atmosphere. Nitric oxide can cause ones blood pressure to drop and cause lethargy and severe headaches if consumed.


Dot and cross diagram of Nitric Oxide
Key: cross = electron of nitrogen
Circle = electron of oxygen

Carbon Monoxide Jeremy Lee (16) 2O1

A harmful chemical which I have found is carbon monoxide. Carbon + Oxygen = Carbon Monoxide (CO).
Carbon monoxide is an odourless and colourless gas which is produced by burning. Examples of carbon-monoxide-producing devices are the gas stove and water heaters. As carbon monoxide is colourless and odourless, it is one of the most common types of air poisoning in various countries. One of its elements, carbon, can be found naturally as diamonds and carbon can also be made into pencil lead. As such, it is a useful to Man. The other element, oxygen, is needed for the survival of all living things. Without oxygen, living things cannot survive.
Key: Cross- Electron of Oxygen, Dot - Electron of Carbon



Phosgene, at room temperature, is a highly toxic, irritating and corrosive gas. It is made up of Chlorine, Carbon and Oxygen (COCl2). It is a colourless, chemically reactive, having an odour like that of musty hay. This colorless gas gained infamy when it was used as a chemical weapon during World War I. It is a major industrial chemical used to make plastics and pesticides.

This shows how three harmless elements can form such a deadly compound. Chlorine is often used commercially as a disinfectant or a purifier. The element Carbon also has many commercial uses, but mainly, it is used as a source of fuel. Carbon can also be used to form Graphite, which is used in the manufacturing of pencil lead. Oxygen is required by all living things to carry out life processes.

Done by: Ryan Lim 2O1(17)

Jiang Qian Feng (11)
Sulfur dioxide

Sulfur dioxide SO2 is formed when one sulfur atom and two oxygen atoms undergo covalent bonding. Sulfur has an atomic number of 16, it is a non-metallic element that is yellow, it is found in the Group VI of the periodic table and this element is often used as a fertiliser. Oxygen has an atomic number of 8, also found in group VI in the periodic table, is used for combustion to take place and is taken in by living things to carry out life processes.

Sulfur dioxide, however, is toxic and harmful, it is often associated with respiratory symptoms and diseases may cause premature death.

The following is a dot-and-cross diagram of this compound.

Calvin Ong(3)
Hydrogen sulfide H2S is colourless, poisonous and flammable gas. It gives out the smell of rotten eggs. It often results from the bacterial breakdown of organic matter in the absence of oxygen, such as in sewers and swamps. It also occurs in volcanic gases, natural gas and water. Thehuman body produces small amounts of Hydrogen sulfide and uses it as a signalling molecule.

Hydrogen sulfide is made up of two hydrogen atoms and sulfur atoms. They undergo covalent bonding. Hydrogen sulfide has a structure similar to that of water.


Gabriel Loye (19)

The harmful compound I chose is ammonia, chemical formula of NH3.

X = Hydrogen
Dot = Nitrogen

Excessive exposure to Ammonia gas can cause respiratory problems, eye irritation and skin problems. These happen as the ammonia that enters the body reacts with water to produce ammonium hydroxide. This chemical is very dangerous as it is corrosive and damages cells in the body. Ammonia gas is colorless and produces a suffocating odour.

Ammonia (NH3) consists of 2 different elements. Both of these elements are harmless and are non-metals, making it a covalent bond. Nitrogen is a gas taking up a large percentage (78%) of the air we breathe in. It has only 1 proton and electron, and is also used in the water we drink (H2O). Nitrogen is also a harmless element. It is also used as a very cold liquid in the form of liquid nitrogen and also in nitric acid.
Despite having harmful properties to our human body, ammonia does have its usefulness in cleaning products.


Hydrogen Peroxide

A harmful compound that is formed from two harmless compounds would be hydrogen peroxide and it’s symbol is H2O2. It is a highly corrosive and dangerous mineral acid. It is a clear liquid which is slightly more viscous than water. Hydrogen peroxide is commonly used as a bleach or cleaning agent. It is highly explosive when it has a high concentration and can corrode human skin. It has a covalent chemical bond.

Hydrogen peroxide is formed from 2 harmless elements, namely hydrogen and oxygen.

Hydrogen, with the symbol H, is the lightest and most abundant chemical element in the Universe, constituting around 75% of the Universe’s elemental mass. Stars are made of hydrogen plasma. Hydrogen is highly combustible and also caused the Hindenburg disaster in 1937.

Oxygen, with the symbol O, is essential to all animals and makes up 21% of the Earth’ atmosphere.

By Travis Ch’ng (32) 2O1


Shamus Lim(25) 2O1


Ammonia is a compound that is made up of the elements Nitrogen and Oxygen in the formula of NH3. It has many uses such as commercial cleaning products. However, it was used during World War II to power buses in Belgium.

Ammonia components, Nitrogen and Oxygen are both harmless elements that are used in our daily lives. Oxygen is an essential part of our survival and takes up a significant part of our atmosphere. Nitrogen is also part of the air we take in (71%) and is harmless. It's hard to believe that these two harmless elements that we use in our daily lives can be combined to be quite dangerous!

Done by Shamus Lim

Toluene (C7H8)
Done by: Lee Wei En, Zen (2O1 15)
Carbon+ Hydrogen-> Toluene

Toluene is formed when 7 carbon atoms, either clear when it is in a diamond form or black when it is in a graphite form, and 8 hydrogen atoms, a colourless gas found most abundantly in the Universe, both of which are harmless to humans, bond through covalent bonding to form a harmful and dangerous compound to man, toluene. Toluene is a dangerous and flammable liquid, which is used in nail polish and hair dye to add gloss. It is also commercially used as a coolant and a booster for fuels. Excessive exposure to toluene may affect the liver and kidneys, the nervous system and skin and eye irritation, causing dizziness, headaches, slower response time, and even death.



Benzene (C6H6)

By : Jaye Chan (2O1 10)

Carbon + Hydrogen --> Benzene

What is it?

Benzene is a colourless and highly flammable liquid. It also has a pleasant odour and evaporates quickly. The vapour of benzene is heavier than air and would sink to low areas. It can be produced either naturally or through human activities. Volcanoes and forest fire can produce benzene and it can also be found in gasoline, crude oil and cigarette smoke.

Why is it harmful?

It enters the body either through inhalation or through the skin. It causes the cells to malfunction. One of the most common effects is where it causes bone marrow not to produce enough red cells and would lead to anemia. It can also damage a person's immunity by changing the level of antibodies in the bloodstream and cause a loss of the white blood cells. More serious problems like death can occur if a person is exposed to high concentration of benzene for a long period of time.

What is it normally used for?

Benzene is mainly used to make other chemicals that can produce useful materials like plastic, resin, nylon and synthetic fibers. It is also used to make certain type of lubricants, rubbers, dyes, detergents, drugs and pesticides.


Ammonia (NH3)

Done by Tan Zhong Chen (29) 2o1

Ammonia is formed from nitrogen and oxygen, two harmless elements. While it is used in agriculture as a fertilizer, used as a refrigerant gas, purification of water, used in the manufacture of plastics, explosives, textiles, pesticides, dyes and household cleaning solutions, exposure to high concentrations of ammonia in the air or in solutions like household cleaners can cause burns to the skin, permanent eye damage, rapid, weak pulserates and burns to the airway.

When nitrogen and oxygen combine, they form covalent bonds. Nitrogen is harmless and constitutes 78% of the earth's atmosphere. Nitrogen is essential for life as it is a consituent of DNA and is thus part of the genetic code. It is mainly used to create ammonia for use in fertilizers. Hydrogen is also mainly used to create ammonia to make fertilizers. As hydrogen is highly combustible, hydrogen fuel cells are being looked into as a possible future fuel. Besides being used commercially to create fertilizers, the combination of hydrogen and nirtogen to ammonia also occurs naturally, in the cracks near volcanoes and when organic materials decay.

(made in paint)


Nitrous Oxide

The chemical equation is N 2 O.
Its constituent elements are nitrogen and oxygen.
Nitrogen is a group 15 element. Nitrogen gas is colourless, odourless, and generally inert. As a liquid it is also colourless and odourless.
Oxygen is a Group 16 element. The gas is colourless, odourless, and tasteless. They bond through covalent bonding, to form nitrous oxide.
Nitrous Oxide is also known as laughing gas. It may sound harmless, but it is very harmful to humans. High levels may be fatal, while lower levels affect the delicate structure of lung tissue. Nitrogen oxide exposure lowers the resistance to such diseases as pneumonia and influenza. Humans exposed to high concentrations suffer lung irritation and potentially lung damage. Lower levels may also cause respiratory diseases. Whereas, its constituent elements, nitrogen and oxygen are harmless.

- Brandon Tan 2O1 (01)

Elmer Yap 2O133

Nitrogen Oxide NO2


Nitrogen + Oxygen

NO2 can irritate the lungs and lower resistance to respiratory infection. NO2 chemically transforms into nitric acid and, when deposited, contributes to lake acidification. NO2, when chemically transformed to nitric acid, can corrode metals, fade fabrics and degrade rubber. It can damage trees and crops.
Sulfur Dioxide

Sulfur dioxide is a chemical compound with the formula SO2 and it is a poisonous gas released by volcanoes and various industrial processes.

It is a noticeable component in the atmosphere, especially following volcanic eruptions.
Sulfur dioxide is a major air pollutant and has significant impacts upon human health. In addition the concentration of sulfur dioxide in the atmosphere can influence the habitat suitability for plant communities as well as animal life. They may also cause acid rain, which kills plant life.


Cai Sheng Hao (02) 2o1

Carbon (C) + Oxygen (O) → Carbon Monoxide (CO)
Carbon monoxide is a colourless, odourless and tasteless gas. 2 harmless elements, Carbon (C) and Oxygen (O) combine (covalent bonding) to form the highly toxic Carbon Monoxide, which causes harm to the human body when inhaled.
Carbon monoxide inhibits the blood's ability to carry oxygen to body tissues including vital organs such as the heart and brain
When CO is inhaled, it combines with the oxygen carrying hemoglobin of the blood to form carboxyhemoglobin (COHb).
Once combined with the hemoglobin, that hemoglobin is no longer available for transporting oxygen.
Carbon monoxide consists of one carbon atom and one oxygen atom, connected by covalent bonding.


Royce Chan 2O104